Remote data replication is an important part of the Internet, and is widely applied to a computer network environment. Data remote replication includes synchronous replication and asynchronous replication.
In conventional techniques, in a scenario of a small delay (e.g., from Hangzhou to Shanghai), the delay of the synchronous replication may be ignored, which has little effect on the application, wherein an industry standard of multi-regional synchronous replication is a protocol for distributed consensus (such as Paxos protocol). In the asynchronous replication, a sender can resume the logic of the sender (e.g., a non-relational database service (AWS DynamoDB Streaming)) without waiting for a receiver to confirm reception; further, the asynchronous replication employing a transfer service manner provides data consistency maintenance of eventual consistency, and in a transfer service mode, a shared log function with strong consistency takes the place of a data replication mechanism built in an application, which, by replicating a link (e.g., AWS S3 meta consistency maintenance) or pushing some logic to a client terminal (e.g., Clusters of Raw Flash Units), can provide guarantee of data reliability itself.
In a cross-regional scenario, network delay between various regions may reach more than 100 ms. As the delay of the synchronous replication is greater in the cross-regional scenario, the synchronous replication is generally not employed for long-distance data transmission, but the asynchronous replication with strong consistency support and a high throughput rate is employed. During direct asynchronous replication, as the delay is longer, the sender needs to buffer a great amount of data, which may create pressure on the memory of the sender, so that better expansion is impossible. For the shared log function with strong consistency in the transfer service mode, as it is necessary to solve the problem of reliability of the data on a log when a node on the log fails, the logic is relatively complicated, the delay may also be much higher than that of asynchronous replication of local data, and at the same time, a Recovery Point Objective (RPO) cannot be ensured in the case of service failover.
Therefore, in the conventional techniques, the use of the asynchronous replication with strong consistency support and a high throughput rate in the cross-regional scenario results in that the delay of data synchronization is longer and at the same time, the recovery point objective cannot be ensured in the case of service failover.